Heater for textile apparatus



Jan. 14, 1969y w. PARKER 3,421,192

HEATER FOR TEXTILE APPARATUS v Filed March 21, 1967 i f f7 /l/ bug/ 4%/ y Ann /5- United States Patent 3,421,192 HEATER FOR TEXTILE APPARATUS Walter Parker, Wilmslow, England, assignor to Ernest Scragg & Sons Limited Filed Mar. 21, 1967, Ser. No. 624,946 Claims priority, application Great Britain, Mar. 1, 1966,

9,040/66; Mar. 23, 1966, 12,732/66 U.S. Cl. 28-62 14 Claims Int. Cl. D02j13/00 D01h 13/26 ABSTRACT OF THE DISCLOSURE A yarn contact heater for travelling yarn comprises Wall means defining a chamber having two opposite sides one of which has an outer surface over which the travelling yarn moves. At the other side heating means is in contact with the wall means. A liuid is in the chamber and transmits heat from the heating means at the one side to the other side provided with the yarn contacting surface. Guide means located within the chamber serves to guide fluid by convection away from the side having the yarn contacting surface but towards a region of that side at which lthe yarn rst contacts the surface and thus causes a drop in the temperature of the same.

This invention relates to contact heaters for travelling yarn of the type in which a yarn is run in contact with a front surface, usually convexly curved, of a heatconducting, for example, a metal, plate, and having a heating element (such as an electric resistance) behind and in good thermal contact with the plate over part or all of the length of the yarn path over the plate, and whereby a yarn is rapidly heated during the first part of its passage over the plate and held at elevated temperature for the remainder of its said passage.

Such heaters are required to supply more heat to the cold, incoming yarn, to raise its temperature, than to the yarn which is merely being thereafter maintained at elevated temperature. Thus t-he temperature distribution along the heater is liable to change when yarn is on the heater as compared with when yarn is not, and for this reason it is usual, in thermostatically controlled heaters, to have the temperature sensing element located between the ends of the heater. When yarn is removed from contact with a hot heater, therefore, although the sensing point remains at the same temperature, the input end of the heater tends to increase in temperature, while the output end either remains at the same temperature or falls in temperature, depending upon the position of the sensing element.

As yarn processing speeds increase, this tendency of the input end of a heater, suitable for high speed processing, t-o rise in temperature when no yarn is running becomes more marked and leads to difficulties in threadingup the heater if it is desired to operate at a temperature near the melting point of the yarn, since in the yarn-off condition, the temperature of the input end of the heater can rise above the melting -point Iof the yarn, and melt the yarn on contact when threading-up is attempted.

The invention comprises a contact heater for travelling yarn of the type described comprising a uid containing chamber affording said front surface, and carrying heat from a heating element to said surface so as to result in a desired temperature distribution along said surface w-here no yarn is running, and adapted to carry additional heat to the input end of said surface by convection from other parts of the heater when a running yarn is brought into contact with and causes slight cooling at the input end.

The invention also comprises a contact heater for 3,421,192 Patented Jan. 14, 1969 travelling yarn of the type described comprising a fluidcontaining chamber bounded by substantially parallel front and rear walls, the front Wall affording said front surface and the rear wall being in thermal contact with said heating element, and having internal guide means defining a convection path in which fluid can displace laterally of said heater.

Said `guide means may comprise at least one barrier joining the said opposite wall over a substantial length of said chamber extending from a point near to the input end of said surface to a point near to the opposite end of said surface and entirely to one side of the yarn path or all yarn paths over the surface, but lying within the rlateral extent of the heating element.

The chamber may have its rear wall in contact with the heating element over substantially the entire breadth of the chamber and may then have a pair of barriers lying one on each side of the yarn path or all yarn paths over the surface.

The chamber may contain a liquid which does not ll it and the uppermost end or ends of the barriers may be below the level of the liquid when the heater is at a temperature within its working range. The uppermost ends of the barriers may be above the level of the liquid when the yliquid is at room temperature.

The -uid may comprise oil, and when the oil does not fill the chamber, the gas or vapour filled space above the oil may be at reduced pressure at room temperature.

The heater may comprise temperature-sensitive means immersed in the huid, or between the heater and the rear wall of the chamber, or on the face of the heater so as to sense the yarn.

The front surface of the heater may be shaped to provide at least one channel in which the yarn can run.

The invention also comprises a textile yarn processing machine comprising a heater as herein defined.

Said heater may be arranged to afford a substantially vertical yarn path with its input end lowermost. The heater may otherwise be arranged to afford a yarn path inclined with respect to the -longitudinal axis of the machine, and again the input end may be lowermost.

The machine may be a false twist crimping machine, which may comprise feed and take-up means for the yarn and false twisting means downstream of the heater.

One embodiment of a contact heater according to the invention will now he described with reference to the accompanying drawings in which:

FIGURE 1 is a sectional side elevation,

FIGURE 2 is a front elevation showing the heater in position in a false twist crimping machine, and

FIGURE 3 is a section on the line Ill-III ofthe heater shown in FIGURE 2.

The heater comprises a fluid-containing chamber 11 affording said front surface 12, and carrying heat from a heating element 13 to said surface 12 so as to result in a desired temperature distribution along said surface when no yarn is running, and adaptel to carry additional heat to the input end 12a of said surface 12 by convection from other parts of the heater when a running yarn is brought into contact with, and causes slight cooling at the input end 12a.

The uid containing chamber 11 is bounded by substantially parallel front and rear walls 14, 15, the front wall 14 affording said front surface 12 and the rear Wall 15 being in thermal contact with said heating element 13, and having internal guide means 16 defining a convection path in Whics uid can displace laterally of said heater.

Said guide ymeans 16 comprise two barriers 17 joining said opposite walls 14, 15 over a substantial length of said chamber 11 extending from a point near to the input end 12a of said surface 12 to a point near to the opposite end of said surface 12 and lying one on each side of a pair of yarn path-defining grooves 18, 19 over the surface 12. As shown in FIGURE 3, the chamber 11 has its rear Wall 15 in contact with the heating element 13 over substantially the entire breadth of the chamber 11. The outermost parts 13a of the heater 13 are in thermal contact with the chamber 11 in those parts 11a of the chamber which are separated by the barriers 17 from that part affording the grooves 18, 19. The barriers 17 lie within the lateral extent of the heating element 13.

The chamber 11 contains oil which does not fill it and the gas or vapour filled space above the oil is at reduced pressure at room temperature to allow for expansion of the oil relative to the chamber 11 at working temperature. FIGURE l shows the oil levels L1, L2, at working temperature and room temperature respectively, and L1 is seen to be above the level of the tops of the barriers 17 While L2 is seen to be below that level.

The apparatus comprises temperature-sensitive means 21 immersed in the fluid and connected to a temperature controller 22 for controlling the input of electrical energy to the heating element in accordance with variations in the temperature sensed by the temperature-sensitive means 21. The temperature-sensitive means could, however, be located between the heating element 13 and the rear wall 14.

The front surface 12 of the heater is curved convexly and shaped to provide the channels 18, 19 in which the yarn can run.

In operation, the front surface 12 of the heater has a definite temperature distribution along it when no yarn is running and the heating element is switched on. When running yarn is brought into contact with the front face 12 in one or both of the grooves 18, 19, the yarn takes up more heat `from the input end 12a of the front surface 12 which therefore begins to cool. This in turn cools the oil immediately behind it and sets up a convection circulation in which the cold oil displaces laterally of the heater at the input end of the chamber in the directions shown lby the arrows in FIGURE 2 and the displaced cold oil is heated in the parts 11a of the chamber 11 remaining separated by the barriers 17 from that part of the chamber 11 immediately behind the yarn paths 18, 19. The hot, rising oil spills over the tops of the barriers 17 and returns to the input end 12a washing the inner surface of the front wall 14 behind the grooves 18, 19.

Except for the part of the front face 12 defining the grooves 18, 19, the hole of the heater is encased in thermal insulation 23 to minimise heat losses, the heating element 13 lbeing separated from the insulation 23 by a backing plate 20.

FIGURE 2 illustrates the heater in position in a false twist crimping machine in which yarn 24 is withdrawn from packages 25, through guide eyes 26, by feed rollers 27 and passes through the heater to false twist tubes 28 so that the false twist generated by the tubes 28 runs back over the heater as far as the rollers 27. Yarn is withdrawn lfrom the twist tubes 28 by output feed rollers 29 feeding the crimped yarn to wind-up means comprising a package rotating bowl 30, a rotating wind-up packa-ge 31 and transverse means 32. Double end take up is illustrated, but the yarn could be taken up singly.

In this case the heater is arranged to afford a substantially vertical yarn path with its input end lowermost. In another embodiment, not illustrated, the heater is arranged to afford a yarn path inclined with respect to the longitudinal axis of a machine having a plurality of longitudinally spaced apart yarn treatment positions each having supply, false twisting and wind-up means as shown in FIGURE 2.

What I claim is:

1. A contact heater for travelling filamentary material comprising in combination wall means defining an internal chamber provided with a first boundary wall having an external filament-engaging surface over which filamentary material is adapted to move, said surface having an inlet region at which initial Contact takes place between said surface and the filamentary material; a body of fluid in said chamber; heating means operatively associated with said chamber for heating said fiuid whereby the latter transmits heat to said wall means, heating said surface to a predetermined temperature; and channel means operative for increasing the transmission of heat to said input region in response to occurrence of a drop in said predetermined temperature resulting from heat loss on contact with travelling filamentary material.

2. A heater las defined in claim 1, wherein said first boundary wall is provided at one side of said chamber, and said wall means further defining a second boundary wall for said chamber at an opposite side of the latter from said one side.

3. A heater as defined in claim 2, said heating means being associated with said second Iboundary wall in heatexchanging relationship therewith.

4. A heater as `defined in claim 1, said channel means comprising guide means arranged in said chamber and operative for directing a ow of said fluid against said first boundary wall in the area of said inlet region of said surface.

5. A heater as defined in claim 4, said chamber having a predetermined longitudinal extension in direction downstream of said inlet region and said heating means having a predetermined lateral extent in direction transversely of said longitudinal extension; and wherein said guide Imeans comprises `at least one barrier connecting said boundary walls and extending from said inlet region in direction of said longitudinal extension of said chamber within the lateral extent of said heating means but to one side of any path traversed by travelling filamentary material on said surface.

46. A heater as defined in claim 5, said barrier extending from said inlet region over a major part of said longitudinal extension of said chamber.

7. A heater as ydefined in claim 5, said heating means having a lateral extent corresponding substantially to the lateral extent of said chamber; and said guide means further comprising an additional barrier transversely spaced from the first-mentioned barrier Iand also located within the lateral extent of said heating means but to the other side of any path traversed by travelling filamentary material in said surface.

8. A heater as defined in claim 5, wherein said fluid is a body of liquid filling said chamber only to a predetermined level, and wherein said -barrier has an upper end remote from said inlet region and located below said level where said heating means is at a temperature within its operating range and heating said liquid.

9. A heater as defined in claim 8, wherein said .flipper end is above said predetermined level when said liquid is at room temperature.

10. A heater Ias `defined in claim 9, wherein said liquid is oil, and wherein vapor developing from said oil in said chamber above said level is at reduced pressure when said oil is at room temperature.

11. A heater as defined in claim .1, and further comprising temperature-sensitive means immersed in said fluid.

12. A heater las defined in claim 1, said surface being provided with at least one guide channel for travelling filamentary material.

13. A heater as defined in yclaim 12, said guide channel being substantially vertical and having a lower end, and said inlet region of said surface coinciding with said lower end.

14. A heater as defined in claim 1, said channel means also being operative for directing fluid away from the remainder of said first wall means other than in said inlet region, whereby to maintain said remainder 'at a constant temperature.

862,002 3/1961 Great Britain. References Cled 849,607 9/1960 Great Britain. UNITED STATES PATENTS 5 336,935 4/1959 switzerland. figg "1 293j31 STANLEY N. GILREATH, Primm Examiner.

1/ 1963 Scragg 57-34 XR WERNER H. SCHROEDER, Assistant Examiner. 12/1966 scragg 57-34 1/1967 Kodaira 28-62 XR 10 U.s. C1. XR. s/1967 Mattingly et a1 57-34 57-34 FOREIGN PATENTS 

